Descartes says that the model of objective reality is extension.
But Salvia teaches that the essence of reality is not extension but heaviness, mass, and physical solidity. We acquire our sense of reality from the counter-force that greets our acts of pushing against things. Reality, or thingy-ness, is abstracted from the experience of resistance to effort and force.
Could a just-born human learn “thing” by watching videos of bouncing billiards? Movement, yes. Mass, no. What about force? Yes—but not the force that we pressure-knowing ones cognize. You have to press against with desire in order to generate the real semantic meat of mass and thing.